music-video-gen/flow-state/LIBRARY-20.md

Twenty more scenes

The library sat at 42 — seven per family, evenly. Even spread is not the same as useful spread: casting in look/Personality.js disqualifies any scene that does not honour all of the track's signature traits, so the pool a given track draws from is much smaller than the shelf count suggests. space and shape are the thin traits, and they are where a new scene is worth most.

So: twenty scenes, roughly three or four per family, weighted towards space (8 of 20) and shape (7 of 20), and each one written against a named neighbour it must not look like. That second column is the real spec — "no two scenes render the same image" is a gate with a numeric floor, and a scene that cannot say what it is instead of does not exist yet.

Procedure per scene is .claude/skills/build-visualizer/: scaffold, write the scene() body, npm run lint:scenes, checks.html?scene=…, then the full suite before the batch commit.

flow

#	scene	traits	what it is	not like
1	Rain Column	camera, space, style	falling sheets of rain in depth layers, sheared by wind	Smoke Column rises and diffuses; this falls and stays discrete
2	Magnet Lines	shape, camera, style	iron-filing field lines around drifting poles	Curl Flow advects noise; here the field is solved, not sampled
3	Kármán Street	shape, camera, space, style	vortices shedding off a fixed body, drifting downstream	Vortex Drift spins the whole frame; this has one still obstacle and a wake

organic

#	scene	traits	what it is	not like
4	Turing Bloom	camera, style	reaction–diffusion spots and stripes, grown in feedback	Ink Bleed spreads and stops; this reaches a living equilibrium
5	Mycelium Web	camera, space, style	threads creeping over a dark substrate, nodes lighting where they meet	Flora grows upright and symmetric; this is flat, branching and lateral
6	Scale Mosaic	shape, camera, style	phyllotaxis of overlapping scales, breathing	Cell Divide splits; this tiles a surface that never divides

minimal

#	scene	traits	what it is	not like
7	Pendulum Trace	camera, style	one harmonograph curve drawn into a slowly decaying trail	Silk Ribbon is a wide ribbon; this is a single hairline and its ghost
8	Contour Map	camera, space, style	sparse topographic contours of a slow height field	Horizon Lines is a parallel bundle; contours are closed and nested
9	Shoji Grid	shape, camera, style	backlit paper panels with the signature form cut out of them	Moiré Grid interferes; this has four or five panels and holds still
10	Balance Stack	shape, camera, space, style	a few forms stacked on a horizon, long shadows	Salt Flat has one distant object; this one is near and about to fall

structural

#	scene	traits	what it is	not like
11	Suspension Span	shape, camera, space, style	cable curves and towers passing overhead	Girder Lattice is a truss field; this is two curves and a rhythm of hangers
12	Stairwell Descent	camera, space, style	a recursive stairwell seen straight down	Gate Corridor moves through gates; this falls through floors
13	Aqueduct March	shape, camera, space, style	receding arches, tiered	Pylon Grid is open frames; arches are solid and carry a skyline
14	Data Aisle	camera, space, style	two racks of indicators receding to a vanishing point	Neon City is exterior and vast; this is interior and close

geometric

#	scene	traits	what it is	not like
15	Voronoi Shatter	camera, style	drifting Voronoi cells, edges lit, re-seeding on phrase lines	Truchet Fold is a regular grid; these cells are irregular and move
16	Apollonian Gasket	camera, style	circle-inversion packing, infinitely nested	Quasicrystal is additive interference; this is exact recursive geometry
17	Isometric Blocks	shape, camera, style	an isometric field of extruded blocks rising on band energy	Floating Geometry drifts free; this is a solid, gridded, lit surface

glitch

#	scene	traits	what it is	not like
18	Halftone Misprint	camera, style	CMY halftone screens, misregistered	nothing else in the library draws dots
19	Droste Feedback	camera, style	recursive zoom-and-rotate video feedback around a small motif	Time Smear translates; this scales, so the image eats itself
20	Analog Wow	camera, style	tape warp: horizontal wobble, chroma bleed, dropout streaks	Scan Tear and Block Mosh are quantised and blocky; this is continuous and wet

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What landed

All twenty, in six commits, each batch gated before it went in. The library is at 62 scenes: flow, organic, geometric and glitch at ten each, structural and minimal at eleven. space went from 20 scenes to 28 and shape from 21 to 28, which was the point — those are the traits that decide whether a track has anything to cast.

Three things came out of the build that are worth keeping:

A slow axis needs a large, low-frequency area, not a detailed one. Phase 11 compares ten-second averages, and the camera's own drift moves that average by 0.01-0.02 on any high-contrast image. An axis that changes line count, drop density or tier count loses to it; one that changes a wake's width, a colony's extent, a tide level or a deck's height beats it. Seven of the twenty declare an axis. Six do not, and each of those files records the candidates measured and what they scored — Turing Bloom, Voronoi Shatter, Droste Feedback and Analog Wow because a feedback or re-cutting scene's own history moves the average further than any parameter can, Contour Map and Balance Stack because the frame is too empty for anything in it to out-move a slow pan.

Two ways to strobe a whole frame, both found by the flash gate. Driving block heights off the low end made every tower in Isometric Blocks grow together — a frame-wide luminance cycle on the kick, 4/s. A hard recursion cutoff in Apollonian Gasket popped a whole generation of discs in and out as the fold crossed it. Local terms and a faded cutoff fixed both.

Style expressed only as grain is not style. Six of the twenty first shipped with a style response the render gate measured at 11-24 out of 255 — the Side Quest 1 complaint, reproduced from scratch. Putting the track's line weight and edge softness into the actual subject (the dot, the ring, the seam, the course, the band boundary) took them to 86-255.

One check changed: Phase 4's transition control is the sum of the two adjacent shots' motion rather than the larger of them. See the commit; the short version is that a dissolve has both stacks live and a nonlinear blend of two moving stacks moves more than either alone, so the old control was reading its own denominator once the library had calm scenes in it.